OBJECTIVE:
There is a high incidence of Acute Rheumatic Fever (ARF) in young Pacific and Maori New Zealanders. Echocardiography has been shown to detect greater prevalence of rheumatic heart disease (RHD) than cardiac auscultation. We aimed to determine the prevalence of RHD in children from an urban population at high risk for ARF.

METHODS:
Portable echocardiography was conducted in 7/29 randomly selected South Auckland schools on 1142 predominantly Maori and Pacific students aged 10 – 13 years between August 2007 – August 2008. Vivid E (GE) machines were used. Mitral and aortic valves were assessed using parasternal and apical views. Findings were classified as definite, probable or possible RHD according to modified WHO criteria (table). Students with abnormal screening echocardiograms were referred for hospital cardiology review and detailed echocardiography. Hospital echocardiograms were blind-reported by 2 or 3 cardiologists.

RESULTS:
93 (8.1%) had abnormalities suggestive of RHD and 20 (1.8%) had incidental congenital heart defects (CHD). The prevalence of definite and probable RHD was per 20.1/1000 (95% CI 18 – 53), the majority with mild disease. Physiologic regurgitation was diagnosed in 27 students after hospital assessment (false positive screening rate 2.4%).

CONCLUSIONS:
We found high rates of undetected RHD in this population. Echocardiographic screening programmes for RHD combined with secondary prophylaxis have the potential to prevent severe RHD in high-risk populations. RHD screening has resource implications: 10% of the study cohort required careful cardiology evaluation for accurate diagnosis of both RHD and CHD and differentiation from physiologic regurgitation.